The Gordon Conference on cardiac Glycosides will be the first held on this subject. Some aspects of cardiac glycosides have been covered in other symposia and meetings on muscle and/or membrane transport, but there has never been time to explore in depth, controversial topics in a single meeting which involves scientists in the areas of chemical synthesis, x-ray crystallography, computer modeling, receptor binding, enzyme kinetics, measurement of ion transport and contractility and clinical practice. The specific aim of the program will be to discuss data in five areas which are in the forefront of this field. (A) Structural-activity-relationships of cardiac gly cosides and the identification of peptides which make up the receptor for cardiac glycosides on Na,K-ATPase, (B) Allosteric sites which regulate binding of cardiac glycosides to Na,K-ATPase, (C) New techniques which allow better correlation between ion transport and positive inotropy, (D) Criteria for determining whether a new drug is acting via a "digitalis-like" mechanism, (E) Analysis of current clinical use of cardiac glycosides. Because of the widespread use of cardiac glycosides in treatment of congestive heart failure, the conference has direct relevance to health care.